This invention relates to apparatus for use in the stringing of tennis or other racquets.
There are numerous racquet stringing devices that have, over the years, been commercialized or otherwise described in the patented arts. Many of these known devices employ complicated means to fasten new strings in the tension applying device, while others employ complicated tension applying apparatus made up of hand or foot activated levers or screw devices and weights. The stringing devices are neither portable in the sense they could easily be used at home, nor are they of simple enough construction to permit the relatively untrained to use them effectively. The improved stringing machine, to be more fully described hereinafter, is relatively simple in design, completely portable and has the distinct advantage in that it can uniformly apply the desired tension to a racquet string throughout the entire restringing process.
With the available stringing devices the amount of tension is often not uniformly applied during the entire stringing operation. The resultant tension on the strings of a restrung racquet will often be less than the tension originally sought to be applied. These differences of tension result from several factors. First, the new string itself may not have been rigidly clamped by the stringer and through slippage causes a resultant loss of tension in that string. Secondly, many clamps in available stringing devices are not secured themselves so that they flex or move relative to their initial settings, again causing the loss of tension. Similarly, measurement of the tension in the cross strings may indicate a difference of 10 or more pounds of tension compared to the tension of the long strings. This difference can be attributed to the friction encountered in pulling these cross strings through the long strings and to the flexing of the long strings.
The improved racquet stringing machine, to be described hereinafter, will reduce these differences in tension between the long and cross strings by means of its unique design. While these still will be measurable differences in tension between the strings, these differences will be minimal; a marked improvement over existing machines.
There are other differences between the available racquet stringing devices and the instant invention. Consider that two identical racquets strung on the same stringing device even by the same operator will often have noticeable variations in the resultant tension applied to the strings of the two racquets. The improved racquet stringing device described hereinafter is designed to reduce these kinds of variations, too. In the improvable event that slippage should occur in the tensioning clamp, the tensioning drum used in the instant device would automatically rotate to maintain the desired tension. The holding clamp is not likely to move, because the clamp is fixed relative to the stringer frame close to the racquet after a string is clamped.
It is therefore an object of the present invention to provide an improved tension applying apparatus which will, with the use of a constant weight source, apply generally the same tension to a string even though the tension is released and reapplied periodically as a normal procedure in the restring operation.
It is a further object of the invention to provide a machine which is simple to operate and relatively portable.
Another object of the invention is to provide a racquet stringing machine which can be adapted to accept racquets of all sizes, be they wood or metal, large or small.
These and other objects of the invention will become more readily apparent from the drawings, the description of the invention and the appended claims.